Studies of aircraft and missile dynamics frequently involve scale model testing in high speed wind tunnels. Conventional testing involves mounting the workpiece (model) on a solid support member ("sting") in the throat of such a tunnel and recording stresses and vibrations experienced as tunnel flow conditions are changed and as the workpiece attitude with respect to that flow is changed. The within invention allows for free flight simulation in the tunnel by providing limited simultaneous pitch, yaw and roll movement during simulated flights. Such freedom includes lateral and vertical motion of the workpiece in the tunnel airstream. Study of vibration of the scale model during transitions is possible in this mode while it is unreliable or impossible in conventional, fixed sting tunnels. This freedom allows more meaningful measurement of flutter characteristics and gust or buffet response than is possible with a fixed sting mounted model.
Wind tunnel studies provide valuable engineering data on various aspects of aircraft design by relating workpiece reactions in the airstream to physical characteristics of the scaled model tested therein. Instrumentation of the workpiece can quite accurately measure such characteristics as sub-critical dynmamic response, flutter conditions, drag and lift, for extrapolation to full sized, free-space craft design and fabrication.
The within invention provides for such measurements while the model is subjected to programmed or commanded attitudes and conditions as opposed to conventional test methods of measuring forces on a fixed or rigidly controlled article. It yields valuable data on vibration modes and flutter characteristics of the airframe not available from fixed sting testing.